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Ratanapinunchai, J and Madeeyoh, I. Differences in electromygraphic activity of the middle and the lower serratus anterior fibers during open and closed kinematics exercises. J Strength Cond Res 36(7): 1788–1792, 2022—This paper seeks to determine differences in muscle activation between the middle (MSA) and the lower serratus anterior (LSA) fibers during 3 exercises. Fifteen healthy men were recruited for the study. Bench push-up plus (BPUP), unstable BPUP (UPUP), and resisted shoulder flexion (RSF) with 10 repetitions at maximum weight were tested. The normalized electromyographic (EMG) activity of the MSA and the LSA was recorded during isometric scapular protraction for BPUP and UPUP or at 150° shoulder flexion for RSF. Normalization was calculated using maximum voluntary isometric scapular protraction activity (%EMG). The results showed that the ratio of %EMG of MSA:LSA was higher than one in BPUP (1.41 ± 0.36) and UPUP (1.81 ± 0.47), but less than one (0.86 ± 0.27) in RSF. These ratios were statistically significantly different (p < 0.05). The activity of MSA and LSA in RSF was significantly (p < 0.002) higher than that of BPUP and UPUP (%EMG of the MSA = 80.53 ± 26.07, 64.75 ± 23.19 and 55.62 ± 25.56 for the RSF, BPUP, and UPUP, respectively; %EMG of LSA = 95.54 ± 24.15, 50.71 ± 26.32, and 32.26 ± 16.14 for the RSF, BPUP, and UPUP, respectively). There was no difference in the %EMG of MSA and LSA between BPUP and UPUP. The MSA worked more than the LSA in the push-up plus (PUP), but the opposite was found in the RSF exercise. The study suggests different functions of the MSA and the LSA. Different exercises should be used, including a PUP for the MSA and RSF for the LSA, or a combination to emphasize both parts of the SA. [ABSTRACT FROM AUTHOR]

Implicit learning has the potential to improve movement execution and reduce injury risk. Previous research showed beneficial effects of short-term interventions with implicit learning in male athletes. However, research on long-term interventions in female athletes is lacking. The aim of this study was to examine the effects of a 4-week intervention with video instruction on movement execution of SSC, a task that is highly related with anterior cruciate ligament (ACL) injury risk, in female athletes. Twenty talented adolescent female soccer players were part of the control (CTRL, n = 10) or video instruction (VIDEO, n = 10) group. All subjects practiced 4 weeks and received general task instructions. In addition, the VIDEO group received expert video instruction during practice. Lower extremity kinematics and kinetics and vertical ground reaction force of SSC were examined during baseline, immediate post, and 1-week retention tests. After nonlinear registration, differences between each subject and the expert she had seen were determined. These differences were analyzed with SPM1D 2-way ANOVA. No interaction effects between time and group were found (p > 0.05). Main effects of time were found in the frontal plane. In particular, smaller deviations of subjects compared with the seen expert of the knee adduction (p = 0.005, 97.9-100% stance phase [SP]) and hip abduction (p = 0.005,11.5-13.8% SP) and adduction (p < 0.001, 33.4-87.7% SP) moments were found in immediate post compared with baseline. These frontal plane short-term improvements, replicating earlier findings in both sexes, may lower ACL injury risk. The large observed interindividual differences overtime may have concealed the long-term effects of video instruction at the group level. [ABSTRACT FROM AUTHOR]

The International Powerlifting Federation recently changed the regulations concerning the bench press (BP) technique, not allowing an accentuated dorsal arch anymore. We investigated the difference between the flat-back vs. arched-back BP performed by competitive powerlifters as concerns the following parameters: (a) 1 repetition maximum (1RM) and barbell displacement; (b) mean and peak barbell velocity and power, and (c) the excitation of the prime movers. Fifteen highly resistance trained individuals (BP 1RM/body mass ratio: 1.38 ± 0.18) performed the flat-back and arched-back BP at their 50, 70, and 90% of the respective 1RM and performed each lift with the intent to maximally accelerate the barbell. Barbell displacement and velocity, power, and the excitation of the upper and lower pectoralis and triceps brachii were assessed. The 1RM was greater with the arched-back BP (+4.2 Kg, 95% confidence intervals + 0.0/+8.4, effect size [ES]: 0.22), whereas the barbell displacement was greater with the flat-back BP for all loads (ES from 0.40 to 0.61). Greater mean (+0.052 m-s¹, 0.016/0.088, ES: 0.42) and peak barbell velocity (+0.068 m-s¹, +0.026/0.110, ES: 0.27) were observed in the flat- back BP, whereas power did not differ. The excitation of upper and lower pectoralis was similar, while an overall trend for an increased activation of triceps brachii was noted in the arched-back vs. flat-back BP. Interestingly, no between-load difference in the excitation of upper and lower pectoralis was observed (p > 0.05). Depending on the training purposes, both flat-back and arched-back BP may be used. The present outcomes may assist practitioners and competitive powerlifters to inform training session. [ABSTRACT FROM AUTHOR]

Arterial occlusion pressure (AOP) of the brachial artery was measured simultaneously using Doppler ultrasound (US), a hand-held Doppler (HHDOP), and a pulse oximeter (PO) in the dominant (DOM) and nondominant (NDOM) arms of males (n = 21) and females (n = 23) using continuous (CONT) and incremental (INCR) cuff inflation protocols. A mixed-model analysis of variance revealed significant (p, 0.05) overall main effects between AOP measured using a CONT (115.7 ± 10.9) or INCR (115.0 ± 11.5) cuff inflation protocol; between AOP measured using US (116.3 ± 11.2), HHDOP (115.4 ± 11.2), and PO (114.4 ± 11.2); and between males (120.7 6 10.6) and females (110.569.4). The small overall difference (1.8163.3) between US and PO measures of AOP was significant (p, 0.05), but the differences between US and HHDOP and between HHDOP and PO measures of AOP were not significant. There were no overall differences in AOP between the DOM and NDOM arms. Trial-to-trial variance in US measurements of AOP was not significant when using either cuff inflation protocol but was significant when using HHDOP and PO and a CONT cuff inflation protocol. Bland-Altman plots revealed reasonable limits of agreement for both HHDOP and PO measures of AOP. The small differences in US, HHDOP, and PO measurements of AOP when using CONT or INCR cuff inflation protocols are of minimal practical importance. The choice of cuff inflation protocol is one of personal preference. Hand-held Doppler of PO can be used to assess AOP before using blood flow restriction during exercise. [ABSTRACT FROM AUTHOR]

Cross-education has been studied extensively with adults, examining the training effects on contralateral homologous muscles. There is less information on the cross-education effects on contralateral heterologous muscles and scant information comparing these responses between adults and youth. The objective was to compare cross-education training effects in male youth and adults to contralateral homologous and heterologous muscles. Forty-two male children (10-13-years) and 42 adults (18-21-years) were tested before and following an 8-week unilateral, dominant or nondominant arm, chest press (CP) training program or control group (14 subjects each). Unilateral testing assessed dominant and nondominant limb strength with leg press and CP 1 repetition maximum (1RM), knee extensors, elbow extensors (EE), elbow flexors, and handgrip maximum voluntary isometric contraction (MVIC) strength and shot put distance and countermovement jump height. Upper-body tests demonstrated large magnitude increases, with children overall exceeding adults (p = 0.05- p < 0.0001, η² : 0.51, 10.4 ± 11.1%). The dominant trained limb showed significantly higher training adaptations than the nondominant limb for the adults with CP 1RM ( p = 0.03, η² : 0.26, 6.7 ± 11.5%) and EE ( p = 0.008, η² : 0.27, 8.8 ± 10.3%) MVIC force. Unilateral CP training induced significantly greater training adaptations with the ipsilateral vs. contralateral limb ( p = 0.008, η² : 0.93, 27.8 ± 12.7%). In conclusion, children demonstrated greater training adaptations than adults, upper-body strength increased with no significant lower-body improvements, and ipsilateral training effects were greater than contralateral training in adults. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the cardiometabolic and physical effects of 2 timematched high-intensity programs in a real-world environment. Forty-three active and healthy adults (sex =31 men and 12 women; age = 27 + 5 years; peak heart rate [HRpeak] = 190.7 + 10.6 beat·min-1) were randomized to 2 very low-volume protocols (;8 minutes): sprint interval training (SIT) (n=15), burpee interval training (BIT) (n=15), and control (CON) (n=13). Subjects in SIT and BIT performed 5 days of 10 3 4 second "all-out" efforts with 30 seconds of recovery. Body composition, blood pressure, countermovement jump (CMJ), 10-m sprint, shuttle run test (SRT), autonomic modulation, self-efficacy, and intention were evaluated before and after training. Sprint interval training elicited a higher %HRpeak, energy expenditure, rating of perceived exertion category ratio 10 scale, and feeling scale than BIT (p, 0.05). SRTdistance was significantly improved in SIT (p = 0.03, d = 0.62), whereas CMJ height was significantly enhanced in BIT (p=0.0014, d=0.72). Self-efficacy progressively worsened for SIT than for BIT as sessions increased, and significant differences were found in 5X week frequency between protocols (p=0.040, d50.79). No differences in intention to engage were detected between the regimens (p. 0.05). No changes were observed in body composition, blood pressure, 10-m sprint, SRTV-O2max, or autonomic variables with training (p. 0.05). Results exhibit that extremely low-volume SIT improved running performance, whereas BIT increased the vertical jump. [ABSTRACT FROM AUTHOR]

Animal studies show that long-lasting stretching training can lead to significant hypertrophy and increases in maximal strength. Accordingly, previous human studies found significant improvements in maximal voluntary contraction (MVC), flexibility, and muscle thickness (MTh) using constant angle long-lasting stretching. It was hypothesized that long-lasting stretching with high intensity will lead to sufficient mechanical tension to induce muscle hypertrophy and maximal strength gains. This study examined muscle cross-sectional area (MCSA) using magnetic resonance imaging (MRI). Therefore, 45 well-trained subjects (f: 17, m: 28, age: 27.7 ± 3.0 years, height: 180.8 ± 4.9 cm, mass: 80.467.2 kg) were assigned to an intervention group (IG) that stretched the plantar flexors 6 x 10 minutes per day for 6 weeks or a control group (CG). Data analysis was performed using 2-way ANOVA. There was a significant Time x Group interaction in MVC (p < 0.001-0.019, η² = 0.158-0.223), flexibility (p < 0.001, η² = 0.338-0.446), MTh (p = 0.002-0.013, η² = 0.125-0.172), and MCSA(p = 0.003-0.014, η² =0.143-0.197). Post hoc analysis showed significant increases inMVC(d = 0.64-0.76), flexibility (d = 0.85-1.12), MTh (d = 0.53-0.6), and MCSA (d = 0.16-0.3) in IG compared with CG, thus confirming previous results in well-trained subjects. Furthermore, this study improved the quality for the morphological examination by investigating both heads of the gastrocnemius with MRI and sonography. Because stretching can be used passively, an application in rehabilitation settings seems plausible, especially if no commonly used alternatives such as strength training are applicable. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the test-retest reliability, usefulness, and validity of field-based devices, in determining jump height (JH) during a countermovement jump (CMJ). Twenty-one male (22.8 ± 2.4 years; 1.82 ± 0.07 m; 86.0 ± 10.4 kg) and 7 female field sport athletes (20.5 ± 1.5years; 1.65 ± 0.06 m; 65.4 ± 7.2 kg) performed 3 CMJs with data simultaneously recorded using a force plate (criterion measure), Optojump, Output Capture, and Push-Band 2.0. Reliability was determined by intraclass correlation (ICC) and coefficient of variation (CV) analyses. Usefulness was assessed by comparing typical error (TE) with the smallest worthwhile change (SWC), and the validity analyses involved repeated measures analysis of variance with post hoc analysis, Pearson correlation coefficient (r), coefficient of determination, and Bland-Altman 95% limits of agreement analyses. All 3 field-based devices were deemed reliable in assessing CMJ height as the respective ICCs ≥ 0.80 and the CV ≤ 10%. Only the Optojump and Output Capture devices were rated as "good" at detecting the SWC in performance (Optojump SWC: 1.44 > TE: 1.04; Output Capture SWC: 1.47 > TE: 1.05). The Output Capture device demonstrated acceptable validity for CMJ height assessment, whereas the Push-Band 2.0 showed systematic bias when compared with the criterion force plate data. Systematic difference was also evident for the Optojump potentially due to the optical switching-cell position on the Optojump. Although all 3 devices showed excellent reliability, the Optojump and Output Capture devices offer practitioners a cost effective, reliable, and valid method of assessing the smallest worthwhile change in CMJ performance in an applied setting. [ABSTRACT FROM AUTHOR]

Supplemental Digital Content is Available in the Text. Chang, C-C, Chang, C-M, and Shih, Y-F. Kinetic chain exercise intervention improved spiking consistency and kinematics in volleyball players with Scapular Dyskinesis. J Strength Cond Res 36(10): 2844–2852, 2022—Scapular dyskinesis (SD) is a common problem among volleyball players with chronic shoulder pain. This randomized controlled study examined the effectiveness of kinetic chain (KC) training on neuromuscular performance of the scapula and trunk during volleyball spikes. Forty volleyball players with SD and chronic shoulder pain received 4 weeks of KC training or the conventional shoulder exercise training (CT). Shoulder pain was assessed using the visual analogue scale (VAS) every week. The kinematics and muscle activation of the shoulder and upper trunk, and proprioceptive feedback magnitude (PFM) for scapular movement consistency, were recorded at the maximum shoulder flexion (T1) and ball contact (T2) during spiking tasks. The two-way repeated measures analysis of variances was used to assess the between-group differences before and after the intervention. The results showed a significant time by group interaction for the upper trunk rotation (p < 0.001) and PFM (p = 0.03) at T2. The post-hoc test indicated that the KC group significantly increased contralateral rotation of the upper trunk (9.63 ± 4.19° vs. −4.25 ± 10.05°), and improved movement consistency (error: 8.88 ± 11.52° vs. 19.73 ± 12.79°) at T2 compared with the CT group. Significant time effects were also identified for VAS, scapular upward rotation (T1 and T2), upper trunk contralateral side-bending and PFM at T1, and upper trunk contralateral rotation at T2. In conclusion, both KC and CT training would relieve shoulder pain and improve scapular and trunk movement, whereas the KC program was more effective for increasing scapular movement consistency and upper trunk rotation during volleyball spikes. [ABSTRACT FROM AUTHOR]

Martínez-Navarro, I, Montoya-Vieco, A, Collado, E, Hernando, B, Panizo, N, and Hernando, C. Muscle Cramping in the marathon: Dehydration and electrolyte depletion vs. muscle damage. J Strength Cond Res 36(6): 1629–1635, 2022—Our aim was to compare dehydration variables, serum electrolytes, and muscle damage serum markers between runners who suffered exercise-associated muscle cramps (EAMC) and runners who did not suffer EAMC in a road marathon. We were also interested in analyzing race pacing and training background. Nighty-eight marathoners took part in the study. Subjects were subjected to a cardiopulmonary exercise test. Before and after the race, blood and urine samples were collected and body mass (BM) was measured. Immediately after the race EAMC were diagnosed. Eighty-eight runners finished the marathon, and 20 of them developed EAMC (24%) during or immediately after the race. Body mass change, post-race urine specific gravity, and serum sodium and potassium concentrations were not different between crampers and noncrampers. Conversely, runners who suffered EAMC exhibited significantly greater post-race creatine kinase (464.17 ± 220.47 vs. 383.04 ± 253.41 UI/L, p = 0.034) and lactate dehydrogenase (LDH) (362.27 ± 72.10 vs. 307.87 ± 52.42 UI/L, p = 0.002). Twenty-four hours post-race also values of both biomarkers were higher among crampers (CK: 2,438.59 ± 2,625.24 vs. 1,166.66 ± 910.71 UI/L, p = 0.014; LDH: 277.05 ± 89.74 vs. 227.07 ± 37.15 UI/L, p = 0.021). The difference in the percentage of runners who included strength conditioning in their race training approached statistical significance (EAMC: 25%, non-EAMC: 47.6%; p = 0.074). Eventually, relative speed between crampers and noncrampers only differed from the 25th km onward (p < 0.05). Therefore, runners who suffered EAMC did not exhibit a greater degree of dehydration and electrolyte depletion after the marathon but displayed significantly higher concentrations of muscle damage biomarkers. [ABSTRACT FROM AUTHOR]

The article presents information on a research paper which discusses a technical-didactic program, developed by a water polo coach for players to help them in talent development. It used an individual discriminant analysis to identify improvements in players who were divided in two subgroups, one with higher learning rates and the other with lower learning rates.

Hammami, R, Duncan, MJ, Nebigh, A, Werfelli, H, and Rebai, H. The effects of 6 weeks eccentric training on speed, dynamic balance, muscle strength, power and lower limb asymmetry in prepubescent weightlifters. J Strength Cond Res 36(4): 955-962, 2022-This study examined whether 6 weeks of twice-weekly in-season hamstring eccentric training would enhance selected performance-related abilities in prepubescent male weightlifters. Twenty elite weightlifters (11.1 +/- 0.8 years) were randomly split into an eccentric training intervention group (INT n = 10) or a control group (CON) that maintained their standard in-season regimen (n = 10). Pre-intervention and postintervention speed, dynamic balance, muscle strength, power, and lower limb (LL) asymmetry were assessed. Analysis of covariance controlling for maturation was used to determine any differences in the performance variables. There were no significant changes in muscle strength, dynamic balance, or LL asymmetry (all p < 0.05) because of the intervention. Both 10-m (p = 0.001) and 30-m (p = 0.007) sprint speed and agility (p = 0.049) improved to a greater extent in INT compared with the CON group. Similar results were evident for the standing long jump (p = 0.015) and 3 hop test (p = 0.004) where performance improved to a greater magnitude in INT compared with CON groups. This study suggests that eccentric training, undertaken twice weekly for 6-weeks results in positive changes in sprint speed, change of direction speed, and power performance, but not muscle strength, dynamic balance, or LL asymmetry in prepubertal weightlifters. [ABSTRACT FROM AUTHOR]

Mangine, GT, Serafini, PR, Stratton, MT, Olmos, AA, VanDusseldorp, TA, and Feito, Y. Effect of the repetitions-in-reserve resistance training strategy on bench press performance, perceived effort, and recovery in trained men. J Strength Cond Res 36(1): 1–9, 2022—This study examined the effects of the repetitions-in-reserve (RIR) strategy on resistance exercise performance, perceived effort, and recovery. Fourteen resistance-trained men (24.6 ± 3.0 years, 176 ± 5 cm, 85.7 ± 14.0 kg) completed 2 bench press protocols in a randomized crossover fashion. The protocols consisted of 4 sets at 80% of 1 repetition maximum (1RM) to a self-reported 3-RIR and a fifth set to failure or all 5 sets to failure (0-RIR). Barbell kinetics (velocity, rate of force development, and impulse), repetition volume, total work, and ratings of perceived exertion (RPE) were quantified on each set. Barbell kinetics were reassessed during one set of 3 repetitions at 80% 1RM completed at 24-hour, 48-hour, and 72-hour postexercise. Blood samples were collected before and after exercise at 6 hours, 24 hours, 48 hours, and 72 hours and analyzed for concentrations of creatine kinase (CK). Separate, 2-way repeated-measures analysis of variance revealed significant interactions (p < 0.001) where 3-RIR better maintained repetitions and work at greater average velocity (+0.6 m·s−1) and lower RPE (0-RIR = 10; 3-RIR = 8.2) across all sets. No differences were seen between conditions for CK at 6 hours postexercise (3-RIR: 32.2 ± 55.3%; 0-RIR: 40.8 ± 66.0%) or for CK and barbell kinetics at 24 hours to 72 hours postexercise. Although no differences were seen for recovery, the RIR strategy enabled work to be better sustained across sets at a lower perceived effort and higher average velocity. This strategy could be used to manage fatigue and better sustain effort and volume during a resistance training session. [ABSTRACT FROM AUTHOR]

Sargent, C, Lastella, M, Schwerdt, S, and Roach, GD. An individualized intervention increases sleep duration in professional athletes. J Strength Cond Res 35(12): 3407-3413, 2021-Athletes typically obtain less sleep than is generally recommended for healthy adults. The aim of this study was to determine whether individualized feedback could increase sleep duration in professional cricket players in the 3 weeks before the start of the domestic season. Players were randomly assigned to a control group (i.e. no individual feedback; n = 8) or an intervention group (i.e. individual feedback about bedtime, wake time, and sleep duration; n = 7). Night-time sleep and daytime naps were monitored using wrist activity monitors in conjunction with self-report sleep diaries for 1 week before, and 1 week after, the feedback intervention. Cumulative sleep duration was calculated as the sum of the sleep duration for a night-time sleep episode and any naps that occurred on the following day. Differences in cumulative sleep duration before and after the intervention were examined using a mixed-effects analysis of variance. There was an interaction between group and week for cumulative sleep duration (p = 0.039; [eta]2 = 0.6; large). The average cumulative sleep duration was longer (+36 minutes) in the intervention group in week 2 compared with week 1. Individualized feedback can be used to increase sleep duration in professional cricket players. In future, it will be important to determine whether improvements in sleep duration can be maintained throughout the season. [ABSTRACT FROM AUTHOR]

Warming-up before an athletic event is important for performance; however, in some competition scenarios, there is a long wait between completing the warm-up and the event. Thus, potentiation protocols are becoming increasingly popular in a competition environment. The aim of the study was to determine the effects of practical potentiation protocols on 15-m start performance in national level swimmers. Eleven national level swimmers participated in the study. Using a randomized cross-over design, subjects completed a 15-m swimming start following 4 different experimental conditions (swim-specific control, resisted band squat, weighted countermovement jumps, and drop jumps from a 45-cm box), each separated by at least 48 hours. A repeated-measures analysis of variance showed a significant difference in 15- m swimming start performance following different warm-up protocols (F(1.646, 14.810) = 6.968, p 50.01). A post hoc Bonferroni test indicated that 15-m start time was significantly quicker with the band squat protocol compared with the swim-specific protocol (6.65 ± 0.43 vs. 6.78 ± 0.43 seconds, respectively, p = 0.04). The results conclude that practical potentiation protocols are able to enhance 15-m swim start performance when combined with a swim-specific warm-up and supports the use of postactivation potentiation during competitive swimming environments. [ABSTRACT FROM AUTHOR]

Squat exercise variations are widely used and extensively researched. However, little information exists on the goblet squat (GBS) and landmine squat (LMS) and differences between men and women. This study investigated the differences in muscle activity and kinetics between the GBS and the LMS in 16 men and 16 women. Five repetitions of each squat type were performed loaded at 30% of their body mass. Vertical and anteroposterior ground reaction forces for the eccentric and concentric phases and peak vertical force were recorded with a force plate. Electromyographic (EMG) signals were recorded for the vastus medialis (VM), vastus lateralis (VL), semitendinosus (ST), and biceps femoris (BF). Normalized mean EMG values and ground reaction forces were analyzed with repeated measures analysis of variance (p < 0.05). Significant main effects for squat condition and sex were found. The LMS reduced activity in the quadriceps (VM and VL) muscles and vertical forces, while increasing posterior horizontal forces. In the LMS, men showed decreased ST activity, whereas women had decreased BF activity. Women exhibited greater quadriceps activity in both the GBS and LMS and greater ST in the LMS. Women also produced greater eccentric vertical force in both the GBS and LMS and less posterior horizontal forces in the LMS. The LMS may be useful to balance hamstring to quadriceps activity, increase horizontal loading, and reduce vertical loading. Conversely, the GBS can better target quadriceps activity and increase vertical loading. Sex differences should be considered for training programs that include the GBS and LMS. [ABSTRACT FROM AUTHOR]

Cold water immersion (CWI) is regularly used by athletes as a postexercise recovery strategy, but relatively little is understood about potential training adaptations associated with habitual use. The aim of this study was to investigate the influence of repeated CWI or a sham intervention on adaptations to a lower body resistance training program. Thirteen men (26 66 years; 83.6 615.7 kg) familiar with resistance training were allocated into a CWI (10 minutes at 10 ̊ C) or sham group and completed 2 x 4-week blocks of lower body resistance training. Subjects completed a total of 16 training sessions (2 x session·week-1), with each session immediately followed by their allocated recovery intervention. Measures of perceptual markers, muscle function, and muscle architecture were recorded at baseline, midpoint, and post-training. Data were analyzed using factorial analysis of variances. The training program resulted in significant increases in muscle fibre pennation angle (p < 0.009), isometric peak force (p = 0.018), and 1/4 squat (p< 0.001) with no differences between groups (all p > 0.05). There were no differences in perceptual responses between groups. Despite the popularity of CWI as a postexercise recovery intervention, the findings from the present study demonstrated no functional or perceptual benefit compared with a sham intervention during progressive strength and power training. Furthermore, there was no detrimental impact of CWI on morphological adaptations after 16 exposures. These findings are important for athletes and practitioners wishing to use CWI as an acute recovery strategy after training, without blunting potential training adaptations. [ABSTRACT FROM AUTHOR]

Godoy, DF, Cadore, EL, Feitosa, WG, Correia, RdA, and Castro, FAdS. Oxygen uptake of wave surfers and complementary parameters in front crawl and surfing-paddling tests. J Strength Cond Res 35(9): 2645-2650, 2021--The aim of this study was to assess the reliability of the oxygen uptake and complementary parameters (heart rate [HR], blood lactate concentration, and rate of perceived exertion [RPE]) obtained from surfers swimming and paddling in a swimming pool. Fourteen recreational male surfers (37.7 6 4.7 years old) were evaluated in (a) a maximal 300-m front crawl test and (b) paddling in a surfboard test, both at the same intensity and for the same duration. Peak oxygen uptake (V̇O2peak) during the tests (direct method), HR, blood lactate concentration (LA), and RPE were assessed. Two-way analysis of variance, a simple Student t test, effect size calculation, intraclass correlation coefficient, and limits of agreement were applied. In general, the tests presented similar results (except for HR), with low agreement, high intraclass correlation, and average to large effect sizes between swimming and paddling. The results suggest that surfers training in a swimming pool should not simply be swimming. Front crawl swimming and surf paddling are 2 distinct actions that should be practiced and tested on their own merits rather than assumed to be interchangeable. [ABSTRACT FROM AUTHOR]

Women have recently been integrated into ground close combat positions; however, there are limited data in women in these roles. We aimed to test the hypothesis that there would be no sex-specific neuromuscular responses, but hormonal signaling would be differentially impacted when exposed to simulated military operational stress (SMOS). Neuromuscular performance was assessed daily using a tactical mobility test (TMT) in 54 male and 15 female military members. Blood was drawn before/after TMT. Mood states were assessed each morning. Unloaded 300-m shuttle time increased 6% in both sexes and remained 7% higher after 1 day of recovery compared with baseline (p<0.05 for both), whereas performance was maintained in other TMT events (p>0.05). Growth hormone increased in men, but not women, before to after TMT (p, 0.001 vs. p 5 0.086). Women experienced a greater decline in insulin-like growth factor-I across days compared with men (npp 5 0.778 vs. 0.209, respectively, p, 0.001). Brain-derived neurotrophic factor increased significantly in men only from before to after TMT on day 1 (men: +107% vs. women: +10%) but no difference on days 3 or 4. Cortisol increased 69% from before to after TMT when averaged by sex and day. Negative mood states (depression, tension, and anger) and altered hormonal concentrations were associated with poorer TMT performance. Acute SMOS differentially impacted circulating hormonal milieu in men and women, but no differences in physical performance responses. Unloaded 300-m shuttle was negatively impacted while other fitness domains were maintained. Relationships between performance and mood/endocrine signaling highlight the potential for self-report measures and biomarkers to serve as indicators of performance change. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare strength, muscle activation, and bar velocity between the traditional (TRAD) and safety squat bar (SSB) back squat. Thirty-two men (21.9463.1 years, 1.7860.8 m, 81.7610.1 kg) volunteered to complete this randomized, crossoverdesign study. Subjects completed 2 separate 1 repetition maximum (1RM) sessions using either the TRAD or SSB. Subsequently, subjects completed 1 session of 3 repetitions at 65 and 85% of their 1RM for each squat condition (SSB & TRAD). Peak muscle activation of 7 muscles from the lower body and trunk was recorded through surface electromyography (EMG), and mean velocity (MV) was recorded by a linear transducer. Electromyography and MV were analyzed by a 2 3 2 (bar 3 load) repeated-measures analysis of variance. A Pearson correlation was used to determine the relationship of 1RM load between bars. Squat 1RM was significantly higher (p, 0.001; 11.6%) for TRAD (144.7 kg) compared with SSB (128.8 kg), and a strong correlation (r 5 0.94) was observed between 1RM values of each bar. A significant main effect was seen in EMG (p, 0.001) and MV for load (p, 0.001). No significant bar 3 load interaction was observed between conditions for any EMG or bar velocity measure (p . 0.05). The SSB produces similar muscle activation and bar velocities compared with the TRAD at relative intensities. However, absolute loads should be adjusted when changing squat bars during a training cycle. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the acute effects of Fat Gripz (FG) on muscular activation and strength. Resistance trained men (n = 15; age = 22.4 6 2.3 years; mass = 83.2 6 11.1 kg) performed 2 experimental trials in a randomized order. Subjects completed 1 repetition maximum (1RM) testing with an Olympic barbell (OB) and with FG attached to an OB during the exercises of deadlift, bent-over row, upright row, concentration curl, and completed maximum repetitions of pull-ups until failure. Surface electromyography (EMG) was used to measure muscle activity from 8 upper extremity muscles (trapezius, medial deltoid, biceps brachii, triceps brachii, flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis, and extensor carpi ulnaris), while performing maximal voluntary isometric contractions during 1RM trials and while performing maximum number of pull-ups. When using the FG, 1RM strength was significantly decreased for each exercise, and the maximal number of pull-ups completed was significantly lower. Electromyography muscle activity was significantly increased in the forearm and shoulder muscles, but significantly decreased in the upper arm muscles with the use of FG during deadlift, bent-over row, and pull-ups. However, there were no differences for EMG activity for upright row and concentration curl. Differences in maximal strength, pull-up performance, and EMG activity with FG use may be due to the different muscle length positions. Although FG training may increase neuromuscular activation, decrements in muscular strength may result in prescribing low training loads that may not be ideal for building muscular strength. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the training load (TL) programming of 3 training groups of a National Collegiate Athletic Association Division I men's college soccer team across a season. Thirty athletes were classified as starters (S), substitutes (NS), or redshirts (RS) based on the percentage of possible minutes played during the season. Training load was quantified at the season, phasic, and weekly levels by the session rating of perceived exertion. Between-group differences were observed at the season level (p < 0.001), and group-by-time interactions for average weekly TL were found at both the phasic (p = 0.04) and weekly levels (p < 0.001). In general, S accumulated greater TL than NS (effect size range for all analyses: -0.59 < d < 1.91) and RS (0.17 < d < 3.67), and NS accumulated greater TL than RS (-0.54 < d < 2.34). Within-group variation at the phasic level was less apparent (-0.35 < d < 1.44); however, all 3 groups displayed training variation at the weekly level (-1.80 < d < 3.24). The session rating of perceived exertion can serve as a low-cost, valid means of quantifying TL in men's college soccer athletes. Practitioners should be especially aware of the possibility of insufficient loading in NS. [ABSTRACT FROM AUTHOR]

To examine the effects of "operationally relevant" loads on postural stability and to determine the effects of unilateral and bilateral strength training programs on postural stability in healthy, recruit-aged men. Fifteen subjects were randomly assigned to either a unilateral (UL; n = 7) or bilateral (BL; n = 8) strength training group, which performed strength training 3 times a week for 4 weeks. Subjects completed the following pretest and post-test assessments: 1 repetition maximum in bilateral (1RM-BL) and unilateral (1RM-UL) stance positions and bilateral and unilateral balance tasks with eyes open and eyes closed. Balance tasks were performed over 3 loading conditions: body mass (BM), 50% BM, and 70% BM. Sample entropy (SE) and root mean square (RMS) were calculated from the center of pressures collected during each balance assessment. The UL strength training group showed significant improvement after training in both 1RM-UL (p < 0.01) and 1RM-BL (p < 0.01). The BL strength training group only showed significant improvement in 1RM-BL (p = 0.01). There was a significant main effect of load on RMS (p < 0.05) across all balance tasks with RMS increasing with increasing load. Sample entropy was found to decrease with increasing load in the unilateral eyes open and bilateral stance tasks. Significant increases in strength (~10 to -29%) were observed; however, increased strength alone is not enough to mitigate the effects of load carriage on the postural control, even when training is performed in stance positions that are posturally challenging. Therefore, "operationally relevant" loads negatively impact postural stability in novice load carriers when assessing nonlinear measures. [ABSTRACT FROM AUTHOR]

Tavares, VDdO, Agricola, PMD, Nascimento, PHD, Oliveira Neto, L, Elsangedy, HM, and Machado, DGS. The effect of resistance exercise movement tempo on psychophysiological responses in novice men. J Strength Cond Res 34(5): 1264-1273, 2020 This study aimed to compare the effects of movement tempo in resistance exercise (RE) on psychophysiological responses in novice men. Seventeen novice men (24.5 ± 3.2 years; 79.3 ± 8.22 kg; 1.76 ± 0.06 m) performed the 10 repetition maximum (10RM) test for bench press and knee extension in 2 sessions (test-retest) and 2 RE training sessions with different movement tempos in a random and counterbalanced order (4 sets of 10 repetitions). The low tempo RE (LTRE) session was performed using 50% 10RM with 3-0-3-0 seconds (concentric, pause, eccentric, and pause, respectively). The moderate tempo RE (MTRE) session was performed using 80% 10RM with 1-0-1-0 seconds (concentric, pause, eccentric, and pause, respectively). Affective valence (Feeling Scale), perceived activation (FAS), attentional focus, and ratings of perceived exertion (Borg 6-20) were reported after each set. A two-way analysis of variance with repeated measures showed only a significant main effect of the set (all ps>0.05), indicating changes between sets but not between LTRE and MTRE. In addition, a paired-samples t-test did not find significant differences between LTRE and MTRE, on average, in any psychophysiological responses (all ps > 0.16). Thus, for the protocol tested, there is no psychophysiological advantage to using either LTRE or MTRE in novice men. From a practical perspective, for psychophysiological responses, the present results suggest that it is up to the trainer∕coach to decide which RE movement tempo to use, which will depend on the purpose of the training period, specificity, client tolerance of and preference for exercise intensity, and movement tempo. [ABSTRACT FROM AUTHOR]

Although forms of integrative neuromuscular training (INT) are used extensively for injury prevention and treatment, no information exists about its effects on performance of adolescent athletes. We investigated the effects of an in-season INT intervention on performance of early-adolescent players using a 2-group, repeated-measures design. Twenty-eight early adolescents were randomly assigned to a control group (CG, participated only in soccer training, N = 14, 11.4 ± 0.57 years, Tanner stage 2.8 ± 0.6) or an experimental group (INT was added to conventional soccer training, N = 14, 11.2 ± 0.5 years, Tanner stage 2.6 ± 0.5). Integrative neuromuscular training (8 weeks, 3 sessions wk−1) aimed to develop core strength, hamstrings eccentric strength, hip∕knee musculature, and dynamic stability using body mass exercises, medicine balls, rocker boards, Bosu, stability balls, etc. Ball shooting speed, speed (10, 20-m), change of direction (COD), jumping performance, and strength were measured before and after training. A 2-way repeated-measures ANOVA was used to analyze data. Integrative neuromuscular training improved 10- and 20-m speed (2.52-2.13 and 3.61-3.39 seconds, respectively, p < 0.05), strength (40.1-44.4 kg, p < 0.05), jumping ability (squat jump: 16.3-17.9 cm; countermovement jump: 19.1- 20.3 cm, p < 0.05), COD (18.0-17.3 seconds, p < 0.05), and shooting speed (73.8-79.0 km h−1, p < 0.05). In the CG, soccer training caused an improvement of smaller magnitude in 10 m and shooting speed (p < 0.05), whereas COD and jumping performance remained unaffected while 20-m speed, COD, and strength deteriorated. These results indicate that an 8-week INT program may induce positive adaptations in performance of early-adolescent soccer players during in-season training, suggesting that INT may be an effective training intervention for this age group. [ABSTRACT FROM AUTHOR]

Different training devices are available to trigger greater activation of the abdominal muscles compared with that achieved during traditional abdominal exercises. This study aimed to compare the electromyographic (EMG) activity of the upper and lower rectus abdominis, external oblique abdominis, erector spinae, and rectus femoris (RF) muscles during traditional crunch and exercise using the 5-minute Shaper device. A convenience sample of 15 healthy men (mean ± SD; age: 23.65 ± 4.49 years, body fat percentage: 14.26 ± 3.56%) was selected. All men regularly participated in physical activity. Electromyographic data were collected for 5 repetitions of each abdominal exercise (traditional crunch and exercise using the 5-minute Shaper device at beginner, intermediate, advanced, and extreme levels) in a randomized and counterbalanced manner. Data were collected using simple differential surface electrodes and analyzed using repeated-measures analysis of variance (p < 0.05). Electromyographic signals were quantified using a root-mean-square analysis and normalized using the maximum voluntary isometric contraction. Traditional crunch produced greater or similar EMG activity in the abdominal muscles and minimized RF activity compared to the 5-minute Shaper device, hence, traditional crunch is preferred for training, especially for individuals with weak abdominal musculature and lower back problems. Therefore, the use of the 5-minute Shaper device may be questioned when it is intended to intensify the activity of the abdominal muscles; however, this apparatus may be used if greater variations in training are desired, depending on individual preferences. [ABSTRACT FROM AUTHOR]

Luebbers, PE, Witte, EV, and Oshel, JQ. Effects of practical blood flow restriction training on adolescent lower-body strength. J Strength Cond Res 33(10): 2674-2683, 2019-The purpose of this study was to examine the effects of a practical blood flow restriction (BFR) training program on lower-body strength of high school weightlifters. Twenty-five students were divided into 3 groups. For 6 weeks, each group completed the same resistance training program with the exception of the parallel back squat exercise (2 d[middle dot]wk-1), which was different for each group. One group (HI) completed a traditional high-load (>=65% 1 repetition maximum [1RM]) back squat protocol with 3 sets of low repetitions (<=10). The LO group completed the squat exercise using a relatively light load (<=30% 1RM) for 1 set of 30 repetitions and 3 sets of 15 with 30 seconds of rest between sets. The LO + BFR group followed the same protocol as LO, but did so with blood flow restricted. One repetition maximum back squat tests were conducted before the start of the program and again on conclusion, the values of which were used as the dependent measure. A 3 x 2 (group x time) repeated-measures analysis of variance revealed a significant interaction (p = 0.043). Follow-up tests were conducted to explore the interaction. Paired-sample t -tests for each group indicated a significant increase in leg strength for the LO + BFR group (p = 0.005) but not for the HI (p = 0.142) or LO groups (p = 1.00). This suggests that a practical BFR training program may be effective in increasing 1RM squat performance of high school students. /=30%> [ABSTRACT FROM AUTHOR]

“Ballistic Six" upper-extremity plyometric training for the pediatric volleyball players. J Strength Cond Res 33(5): 1305- 1310, 2019-The Ballistic Six exercise program includes commonly used upper-body exercises, and the program is recommended for overhead throwing athletes. The purpose of the current study was to investigate the effects of a 12-week the Ballistic Six upper-extremity plyometric training program on upper-body explosive power, endurance, and reaction time in pediatric overhead athletes. Twenty-eight female pediatric volleyball players participated in the study. The participants were randomly divided into 2 study groups: an intervention group (upper-extremity plyometric training in addition to the volleyball training; n = 14) and a control group (the volleyball training only; n = 14). All the participants were assessed before and after a 12-week training program for upper-body power, strength and endurance, and reaction time. Statistical comparison was performed using an analysis of variance test. Comparisons showed that after a 12-week training program, the Ballistic Six upper-body plyometric training program resulted in more improvements in an overhead medicine ball throwing distance and a push-up performance, as well as greater improvements in the reaction time in the nonthrowing arm when compared with control training. In addition, a 1 2-week training program was found to be effective in achieving improvements in the reaction time in the throwing arm for both groups similarly. Compared with regular training, upper-body plyometric training resulted in additional improvements in upper-body power and strength and endurance among pediatric volleyball players. The findings of the study provide a basis for developing training protocols for pediatric volleyball players. [ABSTRACT FROM AUTHOR]

Moeskops, S, Oliver, JL, Read, PJ, Cronin, JB, Myer, GD, Haff, GG, and Lloyd, RS. Within- and between-session reliability of the isometric midthigh pull in young female athletes. J Strength Cond Res 32(7): 1892–1901, 2018—To investigate the within- and between-session reliability of the isometric midthigh pull (IMTP) in pre– and post–peak height velocity (PHV) female athletes. Nineteen pre- and 19 post-PHV athletes performed bilateral IMTPs using a custom-designed isometric testing system. Participants attended 3 separate testing sessions and performed 3 trials within each session. Peak force, relative peak force, force at 30, 50, 90, 100, 150, 200, and 250 ms, rate of force development (RFD) within time-specific bands, time to peak force (TPF), and time to peak RFD were obtained for analysis. Within- and between-session reliability for each variable was calculated from repeated-measures analysis of variance, intraclass correlation coefficients (ICCs), and coefficients of variation (CV) with 95% confidence intervals. Within- and between-session measures of absolute and relative peak force were found to be reliable for both pre-PHV (CV ≤ 9.4%, ICC ≥ 0.87) and post-PHV (CV ≤ 7.3%, ICC ≥ 0.92), but systematic bias was evident between sessions in the pre-PHV group, from session 1 to 2. Analyses of force at the specific time points revealed CVs between 19–37% and 5–24% for pre-PHV and post-PHV athletes, respectively. Greater variability was evident in TPF, and all RFD-related variables for pre-PHV (CV ≥ 38%) and post-PHV (CV ≥ 27%) athletes, respectively. The IMTP appears a reliable and safe method for evaluating peak force in young female athletes. Overall, post-PHV athletes were more reliable than pre-PHV athletes, with pre-PHV athletes needing additional familiarization to minimize the influence of systematic bias. [ABSTRACT FROM AUTHOR]

The purpose of this study was to generate normative values for the standing long jump (SLJ) test in 9- to 17.9-year olds and to investigate sex and age-group differences. The sample comprised 8,034 healthy Colombian schoolchildren [boys n = 3,488 and girls n = 4,546; mean (SD) age 12.8 (±2.3) years old]. Each participant performed two SLJ. Centile smoothed curves, percentile, and tables for the third, 10th, 25th, 50th, 75th, 90th, and 97th percentiles were calculated using Cole's Lambda-Mu-Sigma method. The 2-way analysis of variance tests and Cohen's d showed that the maximum SLJ (centimeter) was higher in boys than in girls across age groups (p, 0.01), reaching the peak at 13 years. Posthoc analyses within the sexes showed yearly increases in SLJ in all ages. In boys, the 50th percentile SLJ score ranged from 109 to 165 cm. In girls, the 50th percentile jump ranged from 96 to 120 cm. For girls, jump scores increased yearly from age 9 to 12.9 years before reaching a plateau at an age between 13 and 15.9. Our results provide, for the first time, sex- and age-specific SLJ reference values for Colombian schoolchildren aged 9-17.9 years. The normative values presented in this study provide the basis for the determination of the proposed age- and sex-specific standards for the FUPRECOL (Association for Muscular Strength with Early Manifestation of Cardiovascular Disease Risk Factors Among Colombian Children and Adolescents) Study-Physical fitness battery for children and adolescents. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the effect of a neuromuscular dentistry--designed mouthguard (NMDD) on dynamic movement ability. Forty-two competitive athletes (8 women, 21.9 ± 2.9 years, 66.8 ± 18.8 kg, 1.68 ± 0.11 m; 34 men, 22.8 ± 4.8 years, 77.4 ± 12.7 kg, 1.78 ± 0.08 m) with greater than 2 years' experience in their designated sport were enrolled in the study. Participants completed the Functional Movement Screen (FMS), modified Star Excursion Balance Test (mSEBT), and a single-leg landing (SLL) task. Each subject was tested with 3 separate mouthguard conditions in random order: (a) no mouthguard (NO), (b) over-the-counter boil-and-bite mouthguard (BB; Shockdoctor Gravity, (c) and an NMDD (Pure Power Elite). Data were analyzed using a repeated-measures analysis of variance for each variable. There were no differences between mouthguard conditions in each of the 7 individual components or composite FMS score (p > 0.05). No differences were seen in the anterior, posteromedial, or posterolateral movements of the mSEBT; overall composite score; or time-to-contact measurements (p > 0.05). The BB condition (2.16 Nm⋅kg-1) exhibited higher peak knee valgus moments (pKVM) on the right leg only when compared with the NMDD condition (1.95 Nm⋅kg-1; p = 0.003) but not the NO condition (2.09 Nm⋅kg-1; p = 0.7262) during the SLL task. No differences in pKVM were seen on the left leg (p = 0.324). In conclusion, an NMDD was not effective at enhancing or diminishing measures of dynamic movement ability compared with BB or NO conditions. [ABSTRACT FROM AUTHOR]

The aims of the present study were to generate normative vertical jump height and predicted peak power (Ppeak) data for 9- to 17.9-year-olds and to investigate between-sex and age group differences in these measures. This was a cross-sectional study of 7,614 healthy schoolchildren (boys n = 3,258 and girls n = 4,356, mean [SD] age 12.8 [2.3] years). Each participant performed 2 countermovement jumps; jump height was calculated using a Takei 5414 Jump- DF Digital Vertical (Takei Scientific Instruments Co., Ltd.). The highest jump was used for analysis and in the calculation of predicted Ppeak. Centile smoothed curves, percentiles, and tables for the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles were calculated using Cole's LMS (L [curve Box-Cox], M [curve median], and S [curve coefficient of variation]) method. The 2-way analysis of variance tests showed that maximum jump height (in centimeters) and predicted Ppeak (in watts) were higher in boys than in girls (p < 0.01). Post hoc analyses within sexes showed yearly increases in jump height and Ppeak in all ages. In boys, the maximum jump height and predicted Ppeak 50th percentile ranged from 24.0 to 38.0 cm and from 845.5 to 3061.6 W, respectively. In girls, the 50th percentile for jump height ranged from 22.3 to 27.0 cm, and the predicted Ppeak was 710.1 2036.4 W. For girls, jump height increased yearly from 9 to 1 7.9 years old. Our results provide, for the first time, sex- and age-specific vertical jump height and predicted Ppeak reference standards for Colombian schoolchildren aged 9-17.9 years. [ABSTRACT FROM AUTHOR]

We aimed to determine the gains in explosive movements of male junior soccer players induced by incorporating an 8-week plyometric training program (PTP) into a standard soccer conditioning regimen 5 months after the beginning of the competitive season. Our hypothesis was that PTP would enhance explosive movements, and thus sprint running, repeated shuttle sprint ability (RSSA), agility and the ability to make repeated changes of direction (RCOD). A group of junior soccer players were randomly divided into 2 groups: an experimental group (E, n = 15, age 15.7 ± 0.2 years) and a control group (C, n = 13, age 15.8 ± 0.2 years). The participants in E and C performed training exercises and matches together, but for an 8-week period in the latter part of the season, the experimental group replaced a part of the normal regimen (the tactical session) by a biweekly course of PTP (hurdle and drop jumps). Two familiarization sessions were held 2 weeks before definitive testing. The ability of the players was assessed by 3 agility tests (a sprint test with 1808 turns, a 9-3-6-3-9 m sprint with backward and forward running, and a four 5-m sprint test with turns); 2 repeated sprint tests (RSSA and RCOD); and running times over 5-, 1 0-, 20-, 30-, and 40-m distances. Participants in E showed gains relative to C in sprint times (p ≤ 0.05 for 5, 1 0, and 20 m), and 2 of 3 the RCOD parameters (RCOD best, p ≤ 0.001 ; RCOD total, p ≤ 0.05). However, with the pattern of plyometric training that we adopted, and perhaps because participants were in good initial physical condition, the agility and RSSA test scores remained unchanged. Nevertheless, we conclude that our PTP can be commended to junior soccer players as a means of improving important components of their physical performance. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the effectiveness of a 12-week in-season low-to-moderate load high-velocity resistance training (HVRT) in addition to soccer training as compared with soccer training only on proxies of athletic performance in prepubertal soccer players. Twenty-four male soccer players performed 2 different protocols: (a) regular soccer training with 5 sessions per week (n = 11 ; age = 1 2.7 6 0.3 years) and (b) regular soccer training with 3 sessions per week and HVRT with 2 sessions per week (n = 13; age = 12.8 6 0.2 years). The outcome measures included tests for the assessment of muscle strength (e.g., 1 repetition maximum [1 RM] half-squat tests), jump ability (e.g., countermovement jump, squat jump [SJ], standing long jump [SLJ], and multiple 5-bound tests [MB5s]), linear speed (e.g., 5-, 1 0-, 20-, and 30-m sprint tests), and change of direction (e.g., T-test and Illinois change of direction test). Results revealed significant group x test interactions for the SJ test (p ≤ 0.05, d = 0.59) and the SLJ test (p < 0.01, d = 0.83). Post hoc tests illustrated significant pre-post changes in the HVRT group (SJ: Δ22%, p < 0.001, d = 1.26; SLJ: Δ1.5%, p < 0.001, d = 1.30) but not in the control group. In addition, tendencies toward significant interaction effects were found for the 1 RM half-squat (p = 0.08, d = 0.54) and the 1 0-m sprint test (p = 0.06, d=0.57). Significant pre-post changes were found for both parameters in the HVRT group only (1RM: Δ25%, p < 0.001, d = 1.23; 1 0-m sprint: Δ7%, p < 0.0001, d = 1.47). In summary, in-season low-to-moderate load HVRT conducted in combination with regular soccer training is a safe and feasible intervention that has positive effects on maximal strength, vertical and horizontal jump and sprint performance as compared with soccer training only. [ABSTRACT FROM AUTHOR]

Balance training may have a preconditioning effect on subsequent power training with youth. There are no studies examining whether the sequencing of balance and plyometric training has additional training benefits. The objective was to examine the effect of sequencing balance and plyometric training on the performance of 1 2- to 13-year-old athletes. Twenty-four young elite soccer players trained twice per week for 8 weeks either with an initial 4 weeks of balance training followed by 4 weeks of plyometric training (BPT) or 4 weeks of plyometric training proceeded by 4 weeks of balance training (PBT). Testing was conducted pre- and posttraining and included medicine ball throw; horizontal and vertical jumps; reactive strength; leg stiffness; agility; 10-, 20-, and 30-m sprints; Standing Stork balance test; and Y-Balance test. Results indicated that BPT provided significantly greater improvements with reactive strength index, absolute and relative leg stiffness, triple hop test, and a trend for the Y-Balance test (p = 0.054) compared with PBT. Although all other measures had similar changes for both groups, the average relative improvement for the BPT was 22.4% (d = 1.5) vs. 15.0% (d = 1.1) for the PBT. BPT effect sizes were greater with 8 of 13 measures. In conclusion, although either sequence of BPT or PBT improved jumping, hopping, sprint acceleration, and Standing Stork and Y-Balance, BPT initiated greater training improvements in reactive strength index, absolute and relative leg stiffness, triple hop test, and the Y-Balance test. BPT may provide either similar or superior performance enhancements compared with PBT. [ABSTRACT FROM AUTHOR]

Single limb stance instability is a risk factor for lower extremity injuries. Therefore, the development of proprioception may play an important role in injury prevention. This investigation considered a professional basketball team for 6 years, integrating systematic proprioceptive activity in the training routine. The purpose was to assess the effectiveness of proprioceptive training programs based on quantifiable instability, to reduce ankle sprains, knee sprains, and low back pain through developing refined and long-lasting proprioceptive control. Fifty-five subjects were studied. In the first biennium (2004-2006), the preventive program consisted of classic proprioceptive exercises. In the second biennium (2006-2008), the proprioceptive training became quantifiable and interactive by means of electronic proprioceptive stations. In the third biennium (2008-2010), the intensity and the training volume increased while the session duration became shorter. Analysis of variance was used to analyze the differences in proprioceptive control between groups, years, and bienniums. Injury rates and rate ratios of injury during practices and games were estimated. The results showed a statistically significant reduction in the occurrence of ankle sprains by 81% from the first to the third biennium (p < 0.001). Low back pain showed similar results with a reduction of 77.8% (p < 0.005). The reduction in knee sprains was 64.5% (not significant). Comparing the third biennium with the level of all new entry players, proprioceptive control improved significantly by 72.2% (p < 0.001). These findings indicate that improvements in proprioceptive control in single stance may be a key factor for an effective reduction in ankle sprains, knee sprains, and low back pain. [ABSTRACT FROM AUTHOR]

The purpose of this investigation was to determine the acute effects of heavy and light implements on subsequent overhead back (OHB) shot put performance with a competition weight shot put. This investigation was designed to test the efficacy of heavy implements for potentiating subsequent OHB performance. Participants included 41 athletes (20.9 61.18 years.) from 2 National Collegiate Athletic Association Division I schools in the Midwestern United States (n = 23 male and n = 1 8 female). Mean distance for OHB throw with a competition shot put was examined after treatment (control, light shot put warm-up, and heavy shot put warm-up) through repeated-measures analysis of variance (ANOVA) with post hoc Bonferroni-corrected post hoc analysis. Responses after treatment on the 10-cm visual analog scale (VAS) fatigue were examined through repeated-measures ANOVA and demonstrated a significant main effect for treatment on VAS fatigue (F = 16.463; p = 0.001). The heavy shot put warm-up resulted in the greatest mean performance over the course of the 3 attempts (14.39±1.82 m) followed by the light shot put warm-up (14.18±1.68 m) and the control (14.15±1.70 m). Results of the repeated-measures ANOVA demonstrated a significant main effect for treatment in regard to average distance (F = 6.276; p = 0.003). Post hoc testing suggested that the heavy shot put warm-up resulted in significantly better mean OHB performance than either the light shot put warm-up (t = 2.983; p = 0.0048; ES = 0.472; power = 0.901) or the control shot put warm-up (t = 3.349; p = 0.0018; effect size [ES] = 0.513; power = 0.939). Subsequent analysis examined the relationship between reported fatigue accrued during the overweight shot put warm-up and the change in performance on the OHB throw when compared to the control condition. Analysis revealed that subjects who reported higher levels of VAS fatigue did not perform as well after the overweight treatment (p = 0.0274). [ABSTRACT FROM AUTHOR]

The article cites a study which quantified the relationship between lower extremity lean mass (LELM) percentage and total body lean mass (TBLM) percentage lower extremity force/power production during a countermovement jump (CMJ) in a general population. It informs that the findings have implications in including DXAassessed lean mass percentage as a component for evaluating lower extremity strength and power.

The article cites the findings of a study which analyzed the effect of supplementing normal in-season training by a 10-week lower limb plyometric training program (hurdle and depth jumping), examining measures of competitive potential. The study concluded that adding plyometric training improved important components of athletic performance relative to standard in-season training in young runners.

The article discusses the importance, effects and benefits of physical education for the children during primary school. Topics discussed include fundamental integrative training (FIT) method to enhance children's health and performance skills, statistical analysis of the data collected for investigation and the practical applications to enhance skill performance and muscular strength.

The article reports on research which was conducted to quantify training load, energy intake and physiological adaptations during a rugby preseason using a case study from an elite European rugby union squad. Researchers evaluated 45 players over the course of a 10 week preseason period. They found that markers of physical performance and anthropometry improved in all players over the course of the period and that the training load and energy intake of the athletes seemed appropriate.

The article discusses research assessing the fundamental movements of mixed martial arts (MMA) athletes using the functional movement screen (FMS) test to determine if a four-week intervention program was successful at improving FMS scores. Topics include the importance of strength and conditioning programs in MMAs, muscle imbalance created by anterior dominance, which may lead to injury, and the feasibility of the FMS in identifying movement dysfunctions.

The article discusses research which investigated the effect acute dehydration had on neuromuscular responses in exercised and non-exercised muscles after exercise which was conducted in the heat. Researchers evaluated ten men who cycled in the heat while dehydrated. They found that dehydration led to reduced muscle torque but did not effect muscle activation capacity and that proper hydration during cycling in the heat may attenuate strength impairments caused by water loss in exercised muscles.

The article reports on research which was conducted to investigate lower limb and trunk muscle activation in resistance exercise trained men who performed the back squat exercise and the resisted sled exercise. Researchers evaluated 10 men. They found that there were no significant differences between the two exercises seen during an analysis of electromyographic activity of muscles and concluded that either exercise could be used as part of an athletic training program.

The article discusses research which was conducted to investigate the cardiovascular response which was initiated in elderly hypertensive women after 16 weeks of combined eccentric or traditional resistance and aerobic training. Researchers evaluated 60 hypertensive females between the ages of 60 and 65. They found that a lower level of cardiovascular stress was seen with combined eccentric resistance training and that it was suitable for elderly hypertensive women.

The article reports on research which was conducted to investigate the effect a seven week, 14 session, sled-resisted sprint training program had on acceleration with three different loads according to a % of body mass (BM). Researchers evaluated young male students who sprinted with either a low load, medium or high load. They found that depending on the magnitude of load, the related effects will be attained in different phases of the 40 meter sprint, that that to improve the initial phase of acceleration up to 30 meters, loads of 20% of BM should be used and that to improve high-speed acceleration phases, loads of 5-12.5% of BM should be used.

The article discusses research investigating the influence of the intensity of squat exercises on the subsequent jump performance and the magnitude of postactivation potentiation (PAP) in eight weightlifters approximately 19.8 years old. The authors' conclusion that high-intensity squat exercise is a better conditioning activity for enhancing subsequent jump performance that moderate-intensity squat exercise is discussed.

The article presents research on the effects of trunk and core muscular development in school-aged children on athletic performance and musculoskeletal health maintenance, with a focus on how it relates to the prevention of low back pain (LBP). Topics include core conditioning exercises, core muscular endurance, and muscular fitness tests.

The article presents a study on the use of neutral spine control exercises as a rehabilitation method after lumbar spine fusion (LSF). Surface electromyography was used to measure muscle activity of the rectus abdominis, external oblique, longissimus, and multifidus muscles. Trunk muscles, maximal voluntary isometric contraction (MVIC), visual analog scale (VAS) scores are also discussed.

The article presents a study on the relationship between maximal oxygen consumption (Vo2max) and acute resistance exercise performance, as well as the maximal aerobic capacity and acute metabolic effects of exercise sequencing, with a focus on rest interval (RI) lengths. Resistance training, athletic performance, and strength testing are also discussed.